Book Image

OpenGL Game Development By Example

By : Stephen Madsen, Robert Madsen
Book Image

OpenGL Game Development By Example

By: Stephen Madsen, Robert Madsen

Overview of this book

OpenGL is one of the most popular rendering SDKs used to develop games. OpenGL has been used to create everything from 3D masterpieces running on desktop computers to 2D puzzles running on mobile devices. You will learn to apply both 2D and 3D technologies to bring your game idea to life. There is a lot more to making a game than just drawing pictures and that is where this book is unique! It provides a complete tutorial on designing and coding games from the setup of the development environment to final credits screen, through the creation of a 2D and 3D game. The book starts off by showing you how to set up a development environment using Visual Studio, and create a code framework for your game. It then walks you through creation of two games–a 2D platform game called Roboracer 2D and a 3D first-person space shooter game–using OpenGL to render both 2D and 3D graphics using a 2D coordinate system. You'll create sprite classes, render sprites and animation, and navigate and control the characters. You will also learn how to implement input, use audio, and code basic collision and physics systems. From setting up the development environment to creating the final credits screen, the book will take you through the complete journey of creating a game engine that you can extend to create your own games.
Table of Contents (19 chapters)
OpenGL Game Development By Example
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Creating the user interface


We are now ready to define our user interface, which will consist of 2D screens, text, and buttons. These will all work exactly as they did in RoboRacer2D. Look at the tip in the Getting ready for a splash section earlier in this chapter for a reminder of how to include prebuilt 2D resources in your project.

Defining the text system

The 2D text system is built by first creating a font framework, then creating functions to display text on the screen. Open RoboRacer2D.cpp and copy the following functions. Then paste them into SpaceRacer3D.cpp:

  • BuildFont

  • KillFont

  • DrawText

We are going to add some new variables to handle the data that we want to display. Add the following lines of code to the global variables section of SpaceRacer3D.cpp:

int score;
int speed;
int missionTime;
int asteroidsHit;
int maximumSpeed;

These variables will hold the stats and scoring used by the game:

  • score: This is the current game score

  • speed: This is the current speed of the ship

  • missionTime...